1. Field of the Invention
The present invention relates to an electrical coupling device, and more particularly to a lamp tube coupler provided for cascading fluorescent lamp tubes or light emitting diode lamp tubes to satisfy the intervals of the electrode sockets of the lamp holder.
2. Description of the Related Art
With reference to FIG. 1 for a schematic diagram of a basic assembly of conventional illumination equipment of a fluorescent lamp is shown. The fluorescent lamp mainly comprises a fluorescent lamp tube 11 and a lamp holder 12. The fluorescent lamp tube 11 has a lamp tube body 111 and endcaps 112 at two ends of the body 111. A pair of electrode joints (not shown in the figure) is respectively disposed to each endcap 112.
The lamp holder 12 has a lamp holder body 121 and two electrode sockets 122. Each electrode socket is respectively disposed to two ends of the lamp holder body 121 and has a pair of electrode inserting holes (not shown in the figure). While in use, the fluorescent lamp tube 11 is inserted into the electrode inserting holes of the lamp holder 12 through the electrode joints of the endcaps 112 to achieve the goal of electrical connection.
In recent years, conventional lamp bulbs or fluorescent lamp tubes are gradually replaced with the use of light emitting diode lamps. However, to satisfy all present lamps that react to the transitional demands between new and old products, conventional products such as light emitting diode lamps are usually designed to match the structural type of the present lamps. For example, the shape of a light emitting diode lamp tube also has a light transmissive tube and endcaps and electrode joints that are disposed to two ends of the light transmissive tube by imitating the conventional fluorescent lamp tube. Thus the light emitting diode lamp tube can be commonly applied to the lamp holder of the conventional fluorescent lamp tube.
However, the length of the conventional fluorescent lamp tube is also different since it has different specifications of 10, 20, and 40 watts. Therefore, the fluorescent lamp which is seen on the street is divided into specific specifications with 10, 20, and 40 watts as well. The intervals of the electrode sockets belonging to the different specifications of the fluorescent lamps are different. In principle, only fluorescent lamp tubes with specific lengths can be applied for installation. The foregoing conventional technique has worse applicability and can not interchange lamp tubes with different lengths and specifications. Consequently, the cost of repeatedly purchasing lamp tubes is relatively increased.